New roles forcis-jasmone as an insect semiochemical and in plant defense

Abstract

cis-Jasmone, or (Z)-jasmone, is well known as a component of plant volatiles, and its release can be induced by damage, for example during insect herbivory. Using the olfactory system of the lettuce aphid to investigate volatiles from plants avoided by this insect, (Z)-jasmone was found to be electrophysiologically active and also to be repellent in laboratory choice tests. In field studies, repellency from traps was demonstrated for the damson-hop aphid, and with cereal aphids numbers were reduced in plots of winter wheat treated with (Z)-jasmone. In contrast, attractant activity was found in laboratory and wind tunnel tests for insects acting antagonistically to aphids, namely the seven-spot ladybird and an aphid parasitoid. When applied in the vapor phase to intact bean plants, (Z)-jasmone induced the production of volatile compounds, including the monoterpene (E)-␤-ocimene, which affect plant defense, for example by stimulating the activity of parasitic insects. These plants were more attractive to the aphid parasitoid in the wind tunnel when tested 48 h after exposure to (Z)-jasmone had ceased. This possible signaling role of (Z)-jasmone is qualitatively different from that of the biosynthetically related methyl jasmonate and gives a long-lasting effect after removal of the stimulus. Differential display was used to compare mRNA populations in bean leaves exposed to the vapor of (Z)-jasmone and methyl jasmonate. One differentially displayed fragment was cloned and shown by Northern blotting to be up-regulated in leaf tissue by (Z)-jasmone. This sequence was identified by homology as being derived from a gene encoding an ␣-tubulin isoform.

Airborne Induction and Priming of Plant Defenses against a Bacterial Pathogen

“…Airborne signaling in the context of plant antiherbivore defense has been repeatedly reported and is likely to be a common phenomenon, since herbivoreinduced VOCs serve multiple functions, such as the attraction of predatory arthropods (Turlings et al, 1995;De Moraes et al, 1998;Thaler, 1999;Kessler and Baldwin, 2001), the repellence of herbivores (Birkett et al, 2000;De Moraes et al, 2001), and the within-plant signaling that leads to systemic responses to local damage (Karban et al, 2006;Frost et al, 2007;Heil and Silva Bueno, 2007). In this study, we report that airborne plant-plant signaling can also prime plant resistance against a pathogenic bacterium.…”

Interactions between tomato volatile organic compounds and aphid behaviour

“…This compound has been reported to be repellent for the aphids Sitobion avenae (Bruce et al 2003) and Aphis gossypii (Moraes et al 2009) but highly attractive towards the aphid parasitoid A. ervi (Birkett et al 2000;Sasso et al 2009). These contrasting results can only be explained by a specific plant-mediation.…”

Within-plant signaling by volatiles leads to induction and priming of an indirect plant defense in nature

“…Volatile organic compounds (VOCs) can attract predatory arthropods (6)(7)(8)(9) and/or repel herbivores (10,11) and thus serve as a means of plant defense to herbivores (12). However, volatiles carry information on the attack of the plant and thus can also be used by herbivores to localize their host plants (13)(14)(15), and they may be used by neighboring, yet-undamaged plants to adjust their defensive phenotype accordingly.…”